The present invention relates to an inking device for the type-carrier element of a calculating machine or a similar office machine.
An inking device is known in which the inking roller has the length of a complete line of writing and is arranged parallel to the axis of the type-carrier wheel so as to be in constant contact with the latter. In this device, the inking roller consists of a central hub covered with spongy material soaked or impregnated with ink, and is made to rotate by the type-carrier wheel during its rotation for the selection of characters.
This device is, however, extremely expensive and of short life due to the very hard wear to which the spongy material is subjected, both because of the continuous rubbing of the type-carrier wheel on the inking roller during the axial shifting of the wheel along the writing line and because of the necessity to assure the uniform inking of the type-carrier wheel during the life of the roller.
Another device is known in which a length of ribbon made of fabric having the same length as the writing line and which is placed between the type-carrier element and the recording support. It has a part lodged within a container in contact with a piece of felt saturated with ink so that the ribbon is kept constantly inked through capillary action.
This device is, however, unreliable and of limited life since the ribbon is subjected to the strokes of the type-carrier element during the writing phase.